IR2085S

Product Summary

The IR2085S is a self oscillating half-bridge driver IC with 50% duty cycle ideallysuited for 36V-75V half-bridge DC-bus converters. This product is also suitable forpush-pull converters without restriction on input voltage.Each channel frequency is equal to fosc, where fosc can be set by selecting RT & CT,where fosc ~ 1/(2*RT.CT). Dead-time can be controlled through proper selection of CTand can range from 50 to 200nsec. Internal soft-start increases the pulse width duringpower up and maintains pulse width matching for the high and low outputs throughout the start up cycle. The IR2085S initiates a soft start at power up and after every overcurrent condition. Undervoltage lockout preventsoperation if VCC is less than 7.5Vdc.

Parametrics

IR2085S absolute maximum ratings: (1)High side floating supply voltage: -0.3 to 150 V; (2)Low side supply voltage: 25 V; (3)High side floating supply offset voltage: Vb - 25 to Vb + 0.3 V; (4)High side floating output voltage: Vb - 0.3 to Vb + 0.3 V; (5)Low side output voltage: -0.3 to VCC + 0.3 V; (6)OSC pin voltage: -0.3 to VCC + 0.3 V; (7)Cs pin voltage: -0.3 to VCC + 0.3 V; (8)Allowable offset voltage slew rate: -50 to +50 V/ns; (9)Supply current: 20 mA; (10)Package power dissipation: 1.0 W; (11)Thermal resistance, junction to ambient: 200 ℃/W; (12)Junction temperature: -55 to 150 ℃; (13)Storage temperature: -55 to 150 ℃; (14)Lead temperature (soldering, 10 seconds): 300 ℃.

Features

IR2085S features: (1)Simple primary side control solution to enable half-bridge DC-Bus Converters for 48V distributed systems with reduced component count and board space; (2)Integrated 50% duty cycle oscillator & half-bridge driver IC in a single SO-8 package; (3)Programmable switching frequency with up to 500kHz max per channel; (4)+/- 1A drive current capability optimized for low charge MOSFETs; (5)Adjustable dead-time 50ns – 200ns; (6)Floating channel designed for bootstrap operation up to +100Vdc.

Diagrams